气候变化领域集成服务门户(CCPortal): Stratification and summer protist communities in the Arctic influenced coastal systems of Nunavik (Québec, Canada)

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DOI	10.3389/fmars.2024.1321604
	Stratification and summer protist communities in the Arctic influenced coastal systems of Nunavik (Québec, Canada)
	Jacquemot, Loic; Tremblay, Jean-Eric; Morency, Carlee; Lovejoy, Connie
发表日期	2024
EISSN	2296-7745
起始页码	11
卷号	11
英文摘要	Phytoplankton and other protists in the 3 mu m to 50 mu m size fraction are grazed on by zooplankton and form the base of Arctic marine food webs essential for local indigenous communities. Anthropogenic climate change is increasing stratification over much of the Arctic Ocean and surrounding seas, but the influence of stratification on protist communities in more coastal regions along Eastern Hudson Bay, Hudson Strait and Ungava Bay is little known. We used 18S rRNA and rDNA amplicon sequencing during two consecutive summers (2017 and 2018) and detailed water column properties to compare the 3 mu m to 50 mu m protist communities under contrasting stratification regimes in the Eastern Hudson Bay Complex. We found that the surface mixed layer in Eastern Hudson Bay, which is under the influence of river runoff, was strongly stratified and dominated by mixotrophic and bacterivorous taxa, mostly the dinoflagellates Heterocapsa rotundata and Gymnodiniales spp., and a more diatom-dominated community at the Subsurface Chlorophyll Maximum (SCM), which persisted in deeper colder and more saline water. The massive sequencing effort retrieved seven putative toxic algae from the upper warmer waters of eastern Hudson Bay. These included Pseudo-nitzschia spp. and potentially harmful dinoflagellates, most notably Alexandrium sp. The persistent weaker stratification conditions in Hudson Strait and Ungava Bay in summer favored a different diatom community, dominated by Chaetoceros spp. and Thalassiosira spp., and small photosynthetic flagellates including Phaeocystis pouchetii and Micromonas polaris. As freshwater input increases and stratification intensifies in the Arctic, our findings suggest the summer dinoflagellate-based community seen in coastal Hudson Bay may also be favored in other regions receiving increased river runoff. These conditions could also favor harmful algal events. The Hudson Strait and Ungava Bay protist communities were found nearer the surface and consisted of diverse species able to profit from ongoing nutrient input due to tidal mixing. These results suggest greater resilience in this and other tidally influenced coastal Arctic Bays lacking larger rivers inputs.
英文关键词	stratification; Hudson bay complex; coastal protists; diatoms; dinoflagellates; harmful algae
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Marine & Freshwater Biology
WOS类目	Environmental Sciences ; Marine & Freshwater Biology
WOS记录号	WOS:001160202600001
来源期刊	FRONTIERS IN MARINE SCIENCE
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/290814
作者单位	Laval University; Laval University
推荐引用方式 GB/T 7714	Jacquemot, Loic,Tremblay, Jean-Eric,Morency, Carlee,et al. Stratification and summer protist communities in the Arctic influenced coastal systems of Nunavik (Québec, Canada)[J],2024,11.
APA	Jacquemot, Loic,Tremblay, Jean-Eric,Morency, Carlee,&Lovejoy, Connie.(2024).Stratification and summer protist communities in the Arctic influenced coastal systems of Nunavik (Québec, Canada).FRONTIERS IN MARINE SCIENCE,11.
MLA	Jacquemot, Loic,et al."Stratification and summer protist communities in the Arctic influenced coastal systems of Nunavik (Québec, Canada)".FRONTIERS IN MARINE SCIENCE 11(2024).